Chapter 5

Perception, Motor Development, Learning, and Cognition in

Infancy

•VisionHow do we study infant vision?

Preferential-Looking Technique—Robert Fantz (1961)Habituation

Visual Acuity and Infantscontrast sensitivity

cones on the foveacolor vision

Perception

Visual acuity

An infant’s visual acuity can be estimated by comparing how long the baby looks at a striped pattern such as this one versus a plain gray square of the same size and overall brightness. This simple test, first developed by researchers interested in visual development, is frequently used to diagnose early visual problems. (From Maurer & Maurer, 1988)

© 1999 John Wiley and Sons, Inc. Vasta, 3e Fig. 7.5

Infants Prefer Visual Patterns

(Figure adapted with permission from “The Origin of Form Perception” by R. Fantz, 1961, Scientific American, 204, p 72. Copyright © 1961 by the Scientific American).

© 1999 John Wiley and Sons, Inc. Vasta, 3e Fig. 7.6

Measurement of Infant Eye Movements

© 1999 John Wiley and Sons, Inc. Vasta, 3e Fig. 7.9

Infants Scan Facial Features

Seven week old babies scan faces for certain features:

High contrast borders

Eyes

Visual scanning

The lines superimposed on these face pictures show where two babies fixated on the images. (a) A 1-month-old looked primarily at the outer contour of the face and head, with a few fixations of the eyes. (b) A 2-month-old fixated primarily on the internal features of the face, especially the eyes and mouth. (From Maurer & Salapatek, 1976)

Pattern Perception

Subjective contour

When you look at this figure, you no doubt see a square—what is called a subjective contour, because it does not actually exist on the page. Seven-month-olds also see the overall pattern here and detect the illusory square. (From Bertenthal, Campos, & Haith, 1980)

Object segregation

Infants who see the display at the left of this figure (a) perceive it as two separate objects, a rod moving behind a block. After habituating to the display they look longer at two rod segments than at a single rod (b), indicating that they find the single rod familiar but the two segments novel. If they first see a display with no movement, they look equally long at the two test displays. This result reveals the importance of movement for object segregation. (From Kellman & Spelke, 1983)

Depth PerceptionOptical Expansion

Apparent at 1 month of age

Binocular DisparityApparent at 4 months of age

Monocular Depth Cues (Pictorial Cues)Apparent at 6–7 months of age

•Auditory Perception

Newborns show auditory localization at birth

•Taste and Smell

Taste: Infants show preference for sweet tastes

Smell: By 2 weeks of age, infants recognize their own mother’s breast milk and scent

•Touch

Infants explore with their hands, fingers, mouth, and tongue

Oral exploration is prevalent during the first few months

Around 4 months of age infants begin to explore by rubbing, fingering, probing, and banging objects

•ReflexesInnate, fixed patterns of action that occur in response to particular stimuli

Strong presence of reflexes at birth = healthy nervous system

Grasping, Rooting, Sucking, Tonic Neck Reflex, steppingSome reflexes remain throughout life

Coughing, Sneezing, Blinking, Withdrawing from pain

•Motor MilestonesReachingSelf-locomotion

Visual Cliff

Motor Development

The major milestones of motor development in infancy

The average age and range of ages for achievement of each milestone are shown. Note that these age norms are based on research with healthy, well-nourished North American infants. (Adapted from Santrock, 1988)

•HabituationSpeed of habituation Speed and Duration of looking efficiency ofDegree of novelty preference processing

These 3 factors in infancy are related to IQs at 18

•Perceptual LearningDifferentiation—what elements are invariant or stable (happy tone of voice usually occurs with a happy face)

Affordances—what actions can be performed with objects and situations (rattles are for shaking)

6 Forms of Infant Learning

•Visual ExpectancyInfants form expectations for future events based on past experiences

Infants can anticipate simple sequences

•Classical ConditioningAn Example

Unconditioned Stimulus—insertion of nipple into infant’s mouth

Unconditioned Response—sucking reflexConditioned Stimulus/Neutral Stimulus—baby sees

breast or bottle before receiving nippleConditioned Stimulus—anticipatory sucking

movements begin when infant sees breast or bottleLittle Albert and John B. Watson (1920)

•Instrumental Operant ConditioningMost research focuses on positive reinforcementInfants form contingency relationships

the infant makes a response the infant receives

reinforcementInfants learn they can have an effect on a situationMobile experiments (Rovee-Collier, 1997)

•Observational LearningInfant Imitation

At birth?Clearly evident at 6 months of ageInfants imitate other humans, not objects

•Object PermanenceOccurs earlier than what Piaget predictedStudied using violation-of-expectancy

Infants as young as 3½–4½ months will look longer at impossible events than possible events

•A-Not-B ErrorOccurs earlier than what Piaget predicted and may be dependent on certain factors

Less error with ageLess likely to go back to A if A and B are distinctMore likely to commit error as delay between A and B

trials increasesMore likely to commit error as number of times object

hidden at A increasesBetter at looking than searching

Cognition

Possible versus impossible events

In a classic series of tests of object permanence, Renée Baillargeon and her colleagues first habituated young infants to the sight of a screen rotating through 180 degrees. Then a box was placed in the path of the screen. In the possible event, the screen rotated up, occluding the box, and stopped when it reached the top of the box. In the impossible event, the screen rotated up, occluding the box, but then continued on through 180 degrees, appearing to pass through the space where the box was. Infants looked longer at the impossible event, showing they mentally represented the presence of the invisible box. (From Baillargeon, 1987)

•Physical KnowledgeResearch about objects supporting each other

At 3 months—Does contact exist?At 5 months—What type of contact?At 6½ months—What is the amount of contact?At 12½ months—What is the shape of the object?

Infants’ developing understanding of support relations(Adapted from Baillargeon, 1998)